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Violence erupted across Iraq on Saturday, with dozens of killings reported in shellings, bombings and shootings, authorities said.

Most of the deaths occurred in Anbar province, the Sunni region west of Baghdad where security forces have been squaring off with anti-government fighters.

Soldiers shelled and bombed parts of Falluja, killing 17 people and wounding 21 others, health officials said. This comes as Iraq's military embarks on a large-scale operation to regain control of the city.

Military action, which included the bombing of mosques and houses in Falluja, sparked an exodus of thousands of residents fleeing the fighting, the officials said.

The metropolis look like a "a city of ghosts," Dr. Ahmed Ammar, an emergency room doctor at Falluja General Hospital, told CNN.

"Ninety-nine percent of Falluja citizens had fled the city," and moved to the northern outskirts, he said.

"We don't have enough medical supplies to treat wounded people," Ammar said. "The international community should intervene immediately and stop this mass killings conducted by al-Maliki and his forces." He was referring to Prime Minister Nuri al-Maliki, who is Shiite.

"Fighters are all outside the city, they are not inside. Why is the Iraqi army continuing to shell residential areas? Who would accept that?" Ammar told CNN from an area where he can receive a phone signal.

More than 300 people have been killed and more than 1,300 others have been wounded in the fighting in and around the city since the beginning of the year, authorities said.

In the Anbar capital of Ramadi, two police officers told CNN that Iraqi security forces killed more than 30 anti-government fighters. Some of those fighters are militants from the Islamic State of Iraq and Syria, linked to al Qaeda.

The wave of violence reflects the growing sectarian tension across Iraq, where the Shiite majority prevails in government and the Sunni minority regards itself as political marginalized.

Bombing attacks and a shooting left at least 19 dead and nearly two dozen wounded in other parts of the country, police said.

A suicide car bombing near Dujail on Saturday killed seven people, including four soldiers, police said. The incident occurred at an Iraqi army checkpoint just north of Baghdad.

In northern Iraq, one roadside bombing killed five police officers, another bombing left three civilians dead, and two people were killed in a shooting, police said.

Near Baghdad, a roadside bomb killed two people near an outdoor market.